Refrigerating apparatus



Feb. 26, 1935.

Filed Jan. 2, 1952 R. D. MOINTOSH REFRIGERATING APPARATUS fizverzz ar:

Patented Feb. 26, 1935 UNITED STATES PATENT OFFICE REFRIGERATING APPARATUS Application January 2, 1932, Serial No. 584,467

13 Claims.

My invention is concerned with refrigerators, designed primarily for household use, in which the liquid refrigerant, such as S02, is pumped by a compressor into an evaporator, where the entrance of the liquid supply is controlled by a float valve, and where usually a layer of lubricating oil covers the liquid refrigerant so that gas being drawn off will not bubble up explosively through the liquid so as to carry some of it with it into the vapor return pipe and cause a frost back that is highly objectionable. To assure that this oil layer shall be of the proper depth to operate efficiently, it is necessary that the height to which the float shall rise in closing the valve shall be accurately regulated, and it is the purpose of my invention to provide simple and efficient means whereby this can be quickly done both in installing the refrigerator and in keeping it properly adjusted to take up any wear that may occur in the valve and valve seat.

It is further concerned with such means as above described that is also capable of adjustment so that in transportation the valve cannot be violently forced into contact with its seat by the float-valve connections in case said float valve be accidentally thrown into an abnormal position.

It is further concerned with such means as above described that can be operated from the exterior of the evaporator, and without the necessity of opening up the evaporator to get at the means that is located therein.

To these ends, it consists of the simple construction hereinafter fully described in detail, and particularly pointed out in the claims. 1 To illustrate my invention, I annex hereto a sheet of drawings, in which the same reference characters are used to designate identical parts in all the figures, of which,-

Fig. 1 is a central vertical section through the evaporator, with the rest of the system indicated diagrammatically; and

Fig. 2 is a detail in section on the line 2-2 of Fig. 1.

Referring to the drawing, the numeral 20 designates in general an evaporator, comprising a header or container 21 forming a reservoir for liquid refrigerant, such asSOz, and from which header depends a plurality of refrigerant-conveying ducts 22 for conveying the refrigerant to the zone or place to be refrigerated. Refrigerant is delivered to the header through the refrigerantconveying pipe 24 and is withdrawn through a vapor or return pipe 25. The pipe 24 is connected with a receiver 27, and the pipe 25 is connected to the low-pressure side of a compressor 30, preferably, as shown, to the crank case thereof. The high-pressure side of the compressor is connected with a condenser 31, which in turn is connected with the receiver 27. The compressor is herein shown as driven by a motor 33 which is controlled in response to the pressure within the pipe 25 by means of an automatic switch 34 which connects the motor with the power mains 35.

The header 21, which is herein shown as a refrigerant-containing chamber, may be formed of a drawn sheet-metal tube having one end thereof open, which receives a ring 40 which is suitably sealed in position. A header valve plate 42 is secured to the ring 40 by screws 43 and carries shut-off valves 44 and 45, which are connected, respectively, with the pipes 24 and 25. The head 42 is provided with a passage 47 communicating with the valve 45 and carries an inwardly extending and upwardly sloping tube 48 for conveying gaseous refrigerant from the free space above the liquid in the refrigerating chamber. The head 42 is also provided with a passage 49 communicating with the valve 44 and having screwed to the inner end thereof the valve-seat member 50 having the passage 51 therethrough, which passage has the reduced end forming the seat 52 for the needle valve 53 sliding throughthe guiding aperture 54 formed in the bearing piece 55 screwed onto the member 50. The float 56 is secured to the lever 57 fulcrumed by the pin 58 between the pair of ears 59 extending downwardly and inwardly from the adjustable fulcrum member 60 having the circular recess 61 therein fitting over the bearing piece 55 so that it can be slid back and forth thereon. The needle valve 52 has on its inner end the small head 62 held in engagement with the contact surface or abutment 63 on the lever 57 by the helically-coiled expanding spring 64 surrounding the valve 52 between the head 62 and the adjacent surface of the fulcrum member 60, which is provided with the upwardly extending arm 65 through which is threaded the adjusting screw 66 which is mounted in the aperture 6'? provided in the head 42 to receive it, and which aperture has the packing 68 and the packing nut 69 threaded therein to prevent leakage. An offset in the screw 66 co-operating with the shoulder in the aperture 67 limits the inward movement of the screw 66 and the pin 70 therethrough, and the washer '71 prevents outward movement, so that when the screw 66 is turned by a screwdriver applied to the slot 72 in its head, the fulcrum member 60 can be moved inwardly or outwardly, as occasion demands. A cap nut 73 is preferably threaded into the outer end of the aperture 6'7, to be removed only when access to the screw 66 is desired.

The operation of the adjusting apparatus is as follows: The level of the layer '74 of lubrieating oil is controlled by the customary port 75 in the under side of thepipe 48, since the rush of the gaseous refrigerant through the pipe carries with it any oil that may enter through the port 75, thus keeping the top of the oil layer at a fixed level, and the oil thus carried through the system lubricates the compressor 30. The bottom of the oil layer '74, and consequently its thickness, is controlled by the height of the top of the liquid refrigerant '76, and for the proper functioning of the apparatus by preventing any of the liquid refrigerant entering the tube 48, it is necessary that the oil layer be of at least a certain depth. Owing to its greater specific gravity and amount, the position of the float 56 depends on the height of the liquid refrigerant 76, and in turn the float valve controls said height as follows: When, due to the gasiflcation of the liquid refrigerant '76 in the evaporator 20, its level falls below that indicated in the drawing, the downward movement of the float 56 carries the abutment 63 away from the head 62, and the spring 64 opens the valve 53, and the liquid refrigerant continues to flow in until the level is restored and the valve is closed. This operation continues automatically, and as the lubricating oil circulates with the refrigerant, the layer of oil remains constant. As the valve seat 52 in time becomes worn, the float, to close the valve, has to rise too high for proper operation due to the oil losing too much of its depth because of the rise in the level of the liquid refrigerant, and a frost back occurs, which is remedied by removing the cap nut 73 and applying a screwdriver to the screw 66 and turning it until the fulcrum member 60 has been drawn toward the head far enough so that the valve 53 is closed with the float at the proper low level. When this level is reached can be determined by the disappearance of the frost back, assuming the motor is running, or it can be determined by applying a gage to the vapor or return pipe 25, and observing when it shows the necessary pressure or the desired degree of refrigeration.

In shipping the apparatus for any distance, to prevent possible injury of the valve 53 and the valve seat 52 by accidental jars, it is advisable to adjust the position of the fulcrum block 60 by the screw 66 to a point where any possible movement of the float 56 in the evaporator 20 will not bring the valve 53 into contact with its seat 52, the spring 64;, mcuurse, keeping them out of engagement unless rt is forced by the movement of the float 56. When thus shipped and it is to be installed, the application of a gage to the vapor pipe 25 and the turning of the screw 66 enable the service man to ascertain by the pressure indicated when the proper adjustment is obtained.

While I have herein shown and described my invention as embodied in an apparatus in which oil is present in the evaporator, and in the form which I at present consider best adapted to carry out its purposes, it will be understood that it is capable of modifications and of use in an apparatus without the oil in the evaporator, and

that I do not desire to be limited in the interpretation of the following claims except as may be necessitated by the state of the prior art.

What I claim as new, and desire to secure by Letters Patent of the United States, is:

1. In a refrigerating system, the combination with an evaporating chamber therein adapted to be partially filled with liquid refrigerant upon which is superimposed a layer of lubricating oil, of an outlet pipe therein connected to a vapor pipe and having its main inlet for the gaseous refrigerant above the level of the oil and an opening therein determining the oil level, an inlet for liquid refrigerant, a float valve for controlling the entry of the liquid refrigerant through said inlet, and means operable from the exterior of the evaporating chamber to control the thickness of the oil layer.

2. In a refrigerating system, the combination with an evaporating chamber therein adapted to be partially filled with liquid refrigerant upon which is superimposed a layer of lubricating oil, of an outlet pipe therein connected to a vapor pipe and having its main inlet for the gaseous refrigerant above the level of the oil and an opening therein determining the oil level, in inlet for liquid refrigerant, afloat valve for controlling the entry of the liquid refrigerant through said inlet, and means operable from the exterior of the evaporating chamber to prevent the possible engagement of the float valve with its seat while the chamber is being shipped and also adjustable to control the thickness of the oil layer.

3. In a refrigerating system, the combination with an evaporating chamber therein adapted to be partially filled with liquid refrigerant upon which is superimposed a layer of lubricating oil, of an outlet pipe therein connected to a vapor pipe and having its main inlet for the gaseous refrigerant above the level of the oil and an opening therein determining the oil level, an inlet for liquid refrigerant, a float rising and falling with the level of the liquid refrigerant in the chamber, a valve for said inlet moved toward closing position by the movement of the float, a lever connected to the float and engaging the valve, and means for moving the fulcrum of the lever relative to the inlet to determine the position of the float in which it will close the valve.

4. In a refrigerating system, the combination with an evaporating chamber therein adapted to be partially filled with liquid refrigerant upon which is superimposed-a layer of lubricating oil, of an outlet pipe therein connected to a vapor pipe and having its main inlet for the gaseous refrigerant above the level of the oil and an opening therein determining the oil level, an inlet for liquid refrigerant, a float rising and falling with the level of the liquid refrigerant in the chamber, a valve for said inlet moved toward closing position by the movement of the float, a lever connected to the float and engaging the valve, and means operable from the exterior of the chamber for moving the fulcrum of the lever relative to the inlet to determine the position of the float in which it will close the valve.

5. In a refrigerating system, the combination with an evaporating chamber therein adapted to be partially fllled with liquid refrigerant upon which is superimposed a layer of lubricating oil, of an outlet pipe therein connected to a vapor pipe and having its main inlet for the gaseous refrigerant above the level of the oil and an opening therein determining the oil level, an inlet for liquid refrigerant, a float rising and falling with the level of the liquid refrigerant in the chamber, a valve for said inlet moved toward closing position by the movement of the float and toward opening position by a spring, a. lever connected to the float and engaging the valve.

Ill

and means for moving the fulcrum of the lever relative to the inlet to determine the position of the float in which, it will close the valve.

6. In a refrigerating system, the combination with an evaporating chamber therein adapted to be partially filled with liquid refrigerant upon which is superimposed a layer of lubricating oil, of an outlet pipe therein connected to a vapor pipe and having its main inlet for the gaseous refrigerant above the level of the oil and an opening therein determining the oil level, an inlet for liquid refrigerant, a float rising and falling with the level of the liquid refrigerant in the chamber, a valve for said inlet controlled by the rising and falling of the float, a lever connected to the float and engaging the valve, and means for moving the fulcrum of the lever relative to the inlet to determine the position of the float in which it will close the valve.

7. In a refrigerating system, the combination with an evaporating chamber therein adapted to be partially filled with liquid refrigerant upon which is superimposed a layer of lubricating oil, of an outlet pipe therein connected to a vapor pipe and having its main inlet for the gaseous refrigerant above the level of the oil and an opening therein determining the oil level, an inlet for liquid refrigerant, a float rising and falling with the level of the liquid refrigerant in the chamber, a valve for said inlet moved to closing position as the float rises, a lever connected to the float and co-operating with the valve, a. member movable toward and from the inlet and serving as a fulcrum for the lever, and means operable from the exterior of the evaporating chamber to move said fulcrum member.

8. In a refrigerating system, the combination with an evaporating chamber therein adapted to be partially filled with liquid refrigerant upon which is superimposed a layer of lubricating oil, of an outlet pipe therein connected to a vapor pipe and having its main inlet for the gaseous refrigerant above the level of the oil and an opening therein determining the oil level, an inlet for liquid refrigerant, a float rising and falling with the level of the liquid refrigerant in the chamber, a valve for said inlet moved to closing position as the float rises, a lever connected to the float and co-operating with the valve, a member movable toward and from the inlet and serving as a fulcrum for the lever, and a screw journaled in the end of said chamber and having its end threaded into the fulcrum member.

9. In a refrigerating system, the combination with an evaporating chamber therein adapted to be partially filled with liquid refrigerant upon which is superimposed a layer of lubricating oil, of an outlet pipe therein connected to a vapor pipe and having its main inlet for the gaseous refrigerant above the level of the oil and an opening therein determining the oil level, an inlet for liquid refrigerant, a float rising and falling with the level of the liquid refrigerant in the chamber, a valve for said inlet moved to closing position as the float rises, a lever connected to the float and co-operating with the valve, :3. member movable toward and from the inlet and serving as a fulcrum for the lever, a screw journaled in the end of said chamber and having its end threaded into the fulcrum member, and a cap nut threaded into said end and covering the outer end of the screw.

10. In an evaporator for refrigerating apparatus, the combination with an inlet needle valve, of a float for actuating the valve, and means for adjusting the position of the float relative to the valve seat, said means consisting of a screw mounted by liquid-tight hearings to rotate in the head of the evaporator and extending parallel to the needle of the valve, a fulcrum piece through which the screw is threaded, and a lever to which the fioat is secured fulcrumed on said piece and having an abutment to engage the valve.

11. In an evaporator for refrigerating apparatus, the combination with an inlet needle valve, of a float for actuating the valve, and means for adjusting the position of the float relative to the valve seat, said means consisting of a screw mounted by liquid-tight bearings to rotate in the head of the evaporator and extending parallel to the needle of the valve, a fulcrum piece through which the screw is threaded, a lever to which the float is secured fulcrumed on said piece and having an abutment to engage the valve, and a spring co-operating with the valve to hold its point away from its valve seat and its other end against the abutment.

12. An evaporator head having a bearing therethrough, a screw journaled in said bearing and operable from its outer end, packing and a packing nut surrounding the screw in the hearing, an inlet passage through the head, a valveseat member closing the inner end of the passage, a bearing cylinder on the inner end of the valve-seat member, and a fulcrum member mounted to slide on the bearing cylinder and having an extension thereof through which the inner end of the screw is threaded.

13. An evaporator head having a bearing therethrough, a screw journaled in said bearing and operable from its outer end, packing and a packing nut surrounding the screw in the bearing, an inlet passage through the head, a valveseat member closing the inner end of the passage, a bearing cylinder on the inner end of the valve-seat member, a fulcrum member mounted to slide on the bearing cylinder and having an extension thereof through which the inner end of the screw is threaded, and a cap nut screwed into the outer end of the bearing.

ROBERT D. MCINTOSH. 

